Method and apparatus for manufacturing continuous acrylic acid through propane partial oxidation reaction

Abstract

This invention relates to a method of continuously preparing acrylic acid and an apparatus using the same, the method including: (1) subjecting a feed including propane, oxygen, water vapor and carbon dioxide to partial oxidation using a catalyst, thus obtaining an acrylic acid-containing mixed gas, (2) separating the acrylic acid-containing mixed gas into an acrylic acid-containing solution and a gas byproduct, (3) separating an acrylic acid solution from the separated acrylic acid-containing solution, and (4) recycling the separated gas byproduct into the feed.

The invention claimed is: 
     
       1. A method of continuously preparing acrylic acid, comprising steps of:
 (1) subjecting a feed including propane, oxygen, water vapor and carbon dioxide to partial oxidation using a catalyst, thus obtaining an acrylic acid-containing mixed gas; 
 (2) separating the acrylic acid-containing mixed gas into an acrylic acid-containing solution and a gas byproduct; 
 (3) separating an acrylic acid solution from the separated acrylic acid-containing solution; and 
 (4) recycling the separated gas byproduct into the feed, 
 wherein an amount of the water vapor is 5 to 50 mol% based on a total mol% of the feed and an amount of the carbon dioxide is 40 to 80 mol% based on a total mol% of the feed, and 
 wherein nitrogen is not included in the feed. 
 
     
     
       2. The method of  claim 1 , wherein the gas byproduct includes at least one selected from the group consisting of propane, propylene, oxygen, carbon monoxide, carbon dioxide, and water vapor. 
     
     
       3. The method of  claim 1 , wherein the separated gas byproduct of the step (4) is recycled so as to be suitable for a composition molar ratio of the feed in the step (1). 
     
     
       4. The method of  claim 1 , further comprising oxidizing carbon monoxide into carbon dioxide using a catalyst including at least one selected from the group consisting of rhodium (Rh), iridium (Ir), palladium (Pd), and platinum (Pt), between the steps (1) and (2). 
     
     
       5. The method of  claim 1 , further comprising oxidizing carbon monoxide into carbon dioxide using a catalyst including at least one selected from the group consisting of rhodium (Rh), iridium (Ir), palladium (Pd), and platinum (Pt), during recycling from the step (4) to the step (1). 
     
     
       6. The method of  claim 1 , wherein a molar ratio of the propane to the oxygen is 1:0.5 to 3. 
     
     
       7. The method of  claim 1 , wherein the catalyst is represented by Chemical Formula 1 below:
   MoV a Te b Nb c O x   [Chemical Formula 1]
 
 in Chemical Formula 1, 
 a is a number from 0.006 to 1, 
 b is a number from 0.006 to 1, 
 c is a number from 0.006 to 1, and 
 x is an amount of oxygen bound to other elements and depends on their oxidation state. 
 
     
     
       8. The method of  claim 1 , wherein the partial oxidation is carried out at 200 to 500° C. 
     
     
       9. The method of  claim 1 , wherein the step (b) is performed using an absorption solvent, and the absorption solvent is water. 
     
     
       10. An apparatus for continuously preparing acrylic acid according to the method of  claim 1 , comprising:
 (1) a partial oxidation reactor configured to prepare an acrylic acid-containing mixed gas by subjecting a feed including propane, oxygen, water vapor and carbon dioxide, transferred via a feed transfer line, to partial oxidation using a catalyst; 
 (2) an absorption tower configured to separate the acrylic acid-containing mixed gas into an acrylic acid-containing solution and a gas byproduct and to absorb the acrylic acid-containing solution; 
 (3) a distillation tower configured to separate the acrylic acid-containing solution into an acrylic acid solution; and 
 (4) a recycling transfer line configured to recycle the separated gas byproduct. 
 
     
     
       11. The apparatus of  claim 10 , wherein the recycling transfer line is connected to the feed transfer line or the partial oxidation reactor. 
     
     
       12. The apparatus of  claim 10 , further comprising an oxidation unit containing a catalyst including at least one selected from the group consisting of rhodium (Rh), iridium (Ir), palladium (Pd), and platinum (Pt). 
     
     
       13. The apparatus of  claim 10 , wherein the gas byproduct includes at least one selected from the group consisting of propane, propylene, oxygen, carbon monoxide, carbon dioxide, and water vapor. 
     
     
       14. The apparatus of  claim 10 , further comprising a control unit configured to control the recycling gas byproduct so as to be suitable for a composition molar ratio of the feed, wherein the control unit is provided to the recycling transfer line. 
     
     
       15. The apparatus of  claim 10 , wherein a molar ratio of the propane to the oxygen is 1:0.5 to 3. 
     
     
       16. The apparatus of  claim 10 , wherein the catalyst is represented by Chemical Formula  1  below:
   MoV a Te b Nb c O x   [Chemical Formula 1]
 
 in Chemical Formula 1, 
 a is a number from 0.006 to 1, 
 b is a number from 0.006 to 1, 
 c is a number from 0.006 to 1, and 
 x is an amount of oxygen bound to other elements and depends on their oxidation state. 
 
     
     
       17. The apparatus of  claim 10 , wherein the partial oxidation is carried out at 200 to 500° C. 
     
     
       18. The apparatus of  claim 10 , wherein separation in the absorption tower is performed using an absorption solvent, and the absorption solvent is water.